Field of the Invention
The present invention relates to a conveying unit of a developing apparatus used for an image forming apparatus, such as a copying machine, a printer, or a fax machine, having adopted an electrophotographic system. More specifically, the invention relates to a developing apparatus including a conveying unit having a simple configuration and capable of stirring, conveying, and replenishing developer, and an image forming apparatus including the developing unit.
Description of the Related Art
In the related art, in a case where developer housed in a developing apparatus is used and consumed, a developer replenishment system for replenishing developer anew is used in an electrophotographic image forming apparatus. An example of the developer replenishment system includes a system for replenishing developer by replacing a developer replenishment container, similar to a toner bottle, detachably attachable to the electrophotographic image forming apparatus.
For example, Japanese Patent Laid-Open No. H08-30084 describes a developing apparatus including two stirring-conveying members disposed in parallel and a circulation channel of developer formed. The two stirring-conveying members each include a spiral member fixed around a rotary shaft in order to prevent degraded toner with a low charging amount from unevenly accumulating in a developing apparatus.
However, since the developing apparatus described in Japanese Patent Laid-Open No. H08-30084 includes the two spiral rotary members disposed therein, a structure for rotating and driving each of the rotary members is required. There are problems, such as complexity, an increase in size, and an increase in cost.
Japanese Patent Laid-Open No. 2010-32754 describes a toner replenishing apparatus capable of moving toner to the center by constantly maintaining a direction of a tongue-shaped bend formed on a rotary stirring blade of a stirring member that conveys the toner in a toner housing portion to a toner replenishing portion.
However, the toner replenishing apparatus described in Japanese Patent Laid-Open No. 2010-32754 moves remaining toner in an end portion in a container to the center of the container so as to stir the toner. A sufficient stir is not performed with respect to the end portion side in a rotary shaft direction of the stirring member. Thus, there is a problem that an image without uneven density cannot be acquired.